Amid widespread skepticism, Secretary of State John Kerry is
defending an international deal to limit Iran’s nuclear powers as an important “first
step” in a larger deal to roll back the Middle Eastern country’s ability to
develop a weapon.

“We believe [the deal] now opens the
door to our going into the larger, more comprehensive arrangement by which Iran
will have to prove that its program is really peaceful,” Kerry said on “Face the
Nation” Sunday in an interview with CBS
News State Department correspondent Margaret Brennan.

A group of
international powers that includes the U.S., France, Germany, Britain, China
and Russia signed a deal early Sunday morning that will freeze and roll back
Iran’s nuclear production for six months in exchange for limited sanctions
relief. The deal, which is meant to be a precursor to a longer-term agreement, was reached
after about four days of intensive talks between the P5+1 powers and Iran. It
also came on the heels of high-level, face-to-face talks authorized by President
Obama that had secretly been taking place between Washington and Tehran over the past
year.

The deal was immediately greeted with skepticism and even
outright hostility from U.S. allies, including Saudi Arabia and Israel. Israeli
Prime Minister Benjamin Netanyahu called it an “historic mistake.” Several Republicans in Congress heaped onthe criticism as well.

Kerry, who is scheduled to fly to Israel after Thanksgiving
to smooth over concerns, argued that the U.S. is in a far better position now
that it has some access to Iran’s nuclear sites. Mr. Obama also called Netanyahu Sunday afternoon to discuss the deal, during which time Netanyahu requested that the U.S. and Israel begin immediate consultations about efforts to negotiate a long-term deal with Iran, according to a White House summary of the call.

“Are you telling me we're not better
off being able to get in and see what's happening? Of course we are,” Kerry said on "Face the Nation." “In
each case where they have been able to enrich without our knowing exactly what
they're doing, we will now be able to have greater inspection, greater
knowledge, greater restraint, and that will expand the amount of time it would
take for them to break out and create a nuclear weapon. That makes Israel
safer. That makes the region safer. And we believe it is the right thing to do
to put to test whether or not they will actually show the world they have a
peaceful nuclear program.”

He also said the deal was “based on
facts” and “specific steps” Iran must take, and that they will only receive limited sanctions
relief – between $6 and $7 billion dollars – while the country will
still lose $15 to $20 billion to ongoing sanctions in the coming months.

But he agreed that critics are right
to be skeptical of Iran’s intentions, adding “There are indications that there are
people in Iran who have wanted to pursue a weapons program, that there have
been secret facilities, building some of those efforts towards that program,
and so there's lots of reason. That's why we don't take anything at face value.
That's why you don't take it for granted.”

Kerry noted that the U.S. struck arms
control agreements with the Soviet Union during the Cold War, deals based not
on trust but rather the ability to verify. And he was adamant that the threat
of military force is not off the table, despite assertions to the contrary by Iran’s
foreign minister. He also said the country does not have a right to enrich its
uranium.

“That's one of the reasons why we need
to verify in this process,” Kerry said. “The fact is, the president…has not
taken that threat off the table.”

The president is, of course, partially hamstrung by the U.S.
Congress. Both the Democrat and Republican Whips in the House, Steny Hoyer,
D-Md., and Kevin McCarthy, R-Calif., agreed that the Senate should proceed with
a sanctions bill that Senate Majority Leader Harry Reid, D-Nev., said he will
put on the floor after Thanksgiving.

Still, they urged some restraint, saying that the Senate
could agree to delay the sanctions for the duration of the interim agreement
signed Sunday, or only put them in place if Iran violates their half of the
deal.

"We don't trust Iran. We need to verify,” Hoyer said. “I think it is appropriate that we wait six
months to implement those which will say to the Iranians we need a final deal.
If not, these tougher sanctions will go in to place. Or if you do not follow
this interim agreement those sanctions will go in to place.”

McCarthy said the deal was not significant enough to merit
celebration.

“I would caution the president from overselling this deal.
It is not a full dismantling of the program -- that would be (an) historical deal,”
he said, adding that he doubted that Mr. Obama would receive bipartisan support
for anything less than a full dismantling of Iran’s nuclear program.

“I know they need some type of other news but that would be
the biggest mistake any administration could do to try to make a decision for a
political basis when you're dealing with American and lives around the world,”
he said. “I would hope that would never be the case.”